If we select Legacy option instead of new UEFI in BIOS settings and disable Secure boot option and then install Windows 10 on our computer, does it make any difference in performance and functionality of Windows 10 OS?

Actually I have a Dell AIO PC and I disabled UEFI and Secure Boot options in BIOS settings and enabled Legacy option because it was not allowing me to select boot device options using F12 key at startup. When I enabled Legacy option, it allowed me to use boot devices.

So after enabling Legacy option instead of UEFI, I installed Windows 10. Now I'm worried if I selected UEFI and Secure Boot option, would it provide any improvement in performance?

Agreed. But just after Windows gets to desktop and finishes loading programs.
Most of the time UEFI/GPT boot sequence is way faster than legacy boot, it depends on hardware specs of course.

I want to highlight my preference for legacy or UEFI-CSM boot scheme. UEFI/GPT scheme is a pain in the **s sometimes when I service a machine, you know when the need to enable legacy mode to boot my diagnostic utilities on USB sticks...

its a pain when you need to access another boot drive agreed, but its more secure as now there are boot virus that can remain even after a wipe/reinstall. Now there is uefi boot virus so even uefi isnt 100% secure

its a pain when you need to access another boot drive agreed, but its more secure as now there are boot virus that can remain even after a wipe/reinstall. Now there is uefi boot virus so even uefi isnt 100% secure

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These days, real boot viruses hardly exist...
They where found a lot many years ago.

Many of this relies to the user behind the screen and keyboard.
In 30 years i never had an boot virus or any other virus in my systems.

Agreed Uefi make its better and safe, but you are NOT the OWNER of your SYSTEM anymore, with many computer you buy in the shop.
Some computers still have the option in the Uefi bios to disable this setting, but for many other this option is grayed out, or just not available.

I dare you to do an clean install from dvd or usb stick in an highly secured Uefi bios!

in my experience uefi makes a huge difference over legacy. thew drivers are less buggy so is the os and everything is just faster and more stable for me windows 8-10 ran like gold with uefi but with legacy they always crashed and had major bugs

I agree, I ran some tests few time ago UEFI /Secure Boot vs Legacy /CSM on my Gigabyte Z97 Motherboard with Hard disk or SSD's.
All time gain using UEFI is less than 2 sec with UEFI vs Legacy on HDD and not show on SSD ..
Depend of the Mobo you are using. The Z97 I own is as fast to boot in UEFI or Legacy with the benefit said above by SPDIF.

Be indulgent if my English is not correct, I try to do my best.

Stop hovering to collapse...Click to collapse...Hover to expand...Click to expand...

in my experience uefi makes a huge difference over legacy. thew drivers are less buggy so is the os and everything is just faster and more stable for me windows 8-10 ran like gold with uefi but with legacy they always crashed and had major bugs

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it seems that everbody mixed everything. uefi is just a new mainboard software. before this there was bios.

you mainboard's software (bios or uefi) looks for a bootloader in your system (microsoft's boot manager, or grub or something similar) and loads it. then it is not used anymore. it doesnt have any effect on your drivers, stability, performance etc.

secure boot is just a way to prevent unsigned bootloaders from load. secure boot only exists in uefi systems.

I agree, I ran some tests few time ago UEFI /Secure Boot vs Legacy /CSM on my Gigabyte Z97 Motherboard with Hard disk or SSD's.
All time gain using UEFI is less than 2 sec with UEFI vs Legacy on HDD and not show on SSD ..
Depend of the Mobo you are using. The Z97 I own is as fast to boot in UEFI or Legacy with the benefit said above by SPDIF.

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More or less I can confirm. In my experience UEFI has faster boot time, but noting of dramatic: 2/3 secs on SSD.

it seems that everbody mixed everything. uefi is just a new mainboard software. before this there was bios.

you mainboard's software (bios or uefi) looks for a bootloader in your system (microsoft's boot manager, or grub or something similar) and loads it. then it is not used anymore. it doesnt have any effect on your drivers, stability, performance etc.

secure boot is just a way to prevent unsigned bootloaders from load. secure boot only exists in uefi systems.

UEFI is a piece of s**t. In performance matters, makes NO DIFFERENCE, AT ALL compared to Legacy. Its really a pain in the ass when you are managing another OSes in the same drive, and you for sure will need a UEFI compatible boot manager, which will make you cry your ass when you are trying to configure it work with this damn OS.
In speed, as I said, makes NO DIFFERENCE even more, Legacy is faster on REAL HDDs (aka not ssd).
The main reason you need to ask for yourself is, why do you need UEFI?. Its more secure, NO, its faster? of course NOT, makes your life easier? NO. Then why?.
Of course, if you wanna do the m$ game or any fanboy, buy an SSD, which 10 was supposed to be running on those drives, cause 10 takes LONGER to boot but you wont see a difference when you are on those drives (which they DIE without ANY warning). If you stay with the platter drives, you will see that 10 is slower than any previous OS release.

Staff Member

in my experience uefi makes a huge difference over legacy. thew drivers are less buggy so is the os and everything is just faster and more stable for me windows 8-10 ran like gold with uefi but with legacy they always crashed and had major bugs

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....you just confirmed my stereotypical idea about every M$ fanboy. It is simply not true what you say. 'always crashed.......had major bugs..where?'
I'd say you do not know what UEFI IS at all.

UEFI is a piece of s**t. In performance matters, makes NO DIFFERENCE, AT ALL compared

to Legacy. Its really a pain in the ass when you are managing another OSes in the same drive, and you for sure will need a UEFI compatible boot manager, which will make you cry your ass when you are trying to configure it work with this damn OS.
In speed, as I said, makes NO DIFFERENCE even more, Legacy is faster on REAL HDDs (aka not ssd).
The main reason you need to ask for yourself is, why do you need UEFI?. Its more secure, NO, its faster? of course NOT, makes your life easier? NO. Then why?.
Of course, if you wanna do the m$ game or any fanboy, buy an SSD, which 10 was supposed to be running on those drives, cause 10 takes LONGER to boot but you wont see a difference when you are on those drives (which they DIE without ANY warning). If you stay with the platter drives, you will see that 10 is slower than any previous OS release.

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Since M$ enforced their idea at the UEFI forums UEFI became useless.....they enforced the interconnection of UEFI and GPT boot. GPT boot is a real progress M$'es idea of UEFI not since it restricts.

To say one of those is faster makes no sense at all, since the initialising process has wait states which are responsible how long it takes until the BIOS/UEFI calls the MBR/GPT....

I know this from hundreds of de-compilations of BIOS/EFI when modifying them.

The reason why M$ wanted UEFI is to have more control over the boot chain, they sell this as secure concept, they tie people to it since it can boot GPT..but as we know to boot GPT UEFI is not mandatory.

Nobody actually cares about the 'pre_OS' and needs UEFI and anything what a BIOS could do is sufficient.

....you just confirmed my stereotypical idea of every M$ fanboy. It is simply not true what you say. 'always crashed.......had major bugs..where?'
I'd say you do not know what UEFI IS at all.

Since M$ enforced their idea at the UEFI forums UEFI became useless.....they enforced the interconnection of UEFI and GPT boot. GPT boot is a real progress M$'es idea of UEFI not since it restricts.

To say one of those is faster makes no sense at all, since the initialising process has wait states which are responsible how long it takes until the BIOS/UEFI calls the MBR/GPT....

I know this from hundreds of de-compilations of BIOS/EFI when modifying them.

The reason why M$ wanted UEFI is to have more control over the boot chain, they sell this as secure concept, they tie people to it since it can boot GPT..but as we know to boot GPT UEFI is not mandatory.

Nobody actually cares about the 'pre_OS' and needs UEFI and anything what a BIOS could do is sufficient.

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No matter where you look, every single supposed improvement "sold" in the latest years implies a price to pay in privacy and freedom.

I use all 6 SATA connectors of the MB, plus additional 4, on 2 PCI-E SATA Controllers, and all of them must be able for to use to boot! That's simply impossible with UEFI!

On the other hand, from what I'd seen, the boot process seems only to look faster, but isn't in reality! Until everything, which has to be run at start-up, is really run and working, the time is the same in both processes!

And I'm with Yen regarding what UEFI is all about!

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I use all 6 SATA connectors of the MB, plus additional 4, on 2 PCI-E SATA Controllers, and all of them must be able for to use to boot! That's simply impossible with UEFI!

On the other hand, from what I'd seen, the boot process seems only to look faster, but isn't in reality! Until everything, which has to be run at start-up, is really run and working, the time is the same in both processes!

And I'm with Yen regarding what UEFI is all about!

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Me too! As for technicians like me UEFI is a real PITA as I stated before when trying to boot usb sticks with diagnostic/servicing tools.

Staff Member

No matter where you look, every single supposed improvement "sold" in the latest years implies a price to pay in privacy and freedom.

No matter if comes from M$, Google, Apple and even Linux.

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Sad but true. At Linux it depends on the distro, though.

[SARCASM]
"I am your trusted company, I am an US giant. I know what is good for you and I offer you a very secure system that comes preinstalled with all useful apps you need to make more out of yourself.

Since it should be secure all the time we are controlling it and protect it from malware. You must not change it nor disable our features because when doing so it becomes vulnerable (to freedom).. and we cannot guarantee that you still get what you need (our products)....

Therefore:
We sign the bootloader
We let you not disable auto updates
We collect your data for your safety and to make the best product for you.